Dowel bar protector



Oct. 8, 1946.

DOWEL BAR 'PROTECTOR Filed April 11, 1945 IR. AMGRATH. sR., Erm. 2,408,939

Patented Oct. 8, 1946 Robert A.-MeGrath,-sr., andvEiln E. "MeGathQ Brooklyn, N.- Y.l

Aplication'f'April 11,4 1945, SerialNo.y "5872726" 2 Claims.

This .invention relates `'toidowel bar-protectors" ofthe general'type used inleonstrluctionof conicrete "roadways,

l For tying Ytogether-the 'two sections of the completed-roaciway,4 dow1-bars`1are frequently embedded in the first laidsection bars" at right ang-lesesol astol extend parallel and closeV to" the retaining -raillwhioh confines the concrete along the innerlside'of Athe r's't-.completed road` section.r Then, when! the concrete way;

Unless` the-*bent portions ofi the dowelbars which lie adjacent Ythe-retainingfrailare suitably l proposed?y to# asso'- ciate protectors with the dowel bars to prevent them from becoming covered with concrete. One-such yform of protector is rdisclosed-inPatentNo;-1,987,392 of Charles wise injuring the edge of the roadway.

It is an important object of our invention to provide a protector for dowel bars used in con- Ibent portions 4'of the 4shown a dowel bar crete road construction which'A is adapted ztoiibe f associated 'with' thef projecting:v bent' portions fofA structed and arranged-` ing engagement with 'the concrete :after the 'flatte'r'has set. Y By virtue' crete andi does not require removal therefrom.'

Another 'object a protector ofdth'e aloove'fcharacter whichziin-' cludeslaterally disposed wings@ adapted fito "be concrete inl tight' contact with` 1 the sideirail sofas not ,to: ree' quire'! supplementa'ry.` means; such' ra'si clips orf stakes for retaining thev protector" ini rpositioni A held-by the plastic the Vinner face of preparatory to pourin'gwthe 'concrete-:f

Still another object of our invention is vto pro:

vide aflat blank #of sheet 'materiaL forexample A from whichV our protector can bel-'ffashe ioned on `the ljob' with the simplest Ltoolslandiby-f relatively unskilled Aworkmen` Thus, a suppl-yfoff protectors Cani b'elshipped and stowediinllth'eA asto occupy 'a minimum i amount`- of` space,i andi eifectingila .reduction'i in- 1 transportationcosts, and the blanks can ibeeloen'tl to shape at the time and in the quantitythattheyf are required for use.`

Other objects and advantages wllbe appar# ent 'from' the Vfollowing detaileddescription off al; of the invention; reference 'r preferredembodiment being had to the annexed! drawing in which Figure l isa dowel bars;

Figure-2 l'is asideviewfofftheprotector; Figure -3 is a cross-section taken on the line 3 3 of Fig. 2;

Figure 4 is a cross-section through a portion Figure 5 is a plan view of a blank from which the protector is formed.

Referring to the drawing, in Figs. l and 2 is protector P. The protector comprises an elongated strip of metal folded along a line extending medially throughout its extending laterally outwardly from its two lower edges are wings 2a and 3a, respectively, both lying in a common plane. l

The ends of the casing are pressed together of this construction then: protector` becomesfn'inly embedded inthecom' perspective 'view of afproteetor f'orff of 'the f protector f and held by tie wires e passing through registerway above Ithe other to an extent suilicient to ing holes 5. These ends project longitudinally break or loosen the dowel bars, the smooth faces beyond the corresponding ends of the wings 2a of the wings 2a and 3a allow relative slippage and 3a and are undercut, as indicated at 6, so as between the vertical faces or the road sections to overhang the plane defined by the wings. An and reduces to a large extent the danger of opening 1 is provided in the ridge of the casing cracking of the cement.

adjacent but spaced from one end but located at The blank B shown in Fig. 5 from which the such a distance therefrom, measured lengthwise protector is made is composed of relatively light of the protector, as to lie rearwardly of the tergage sheet metal, this metal being of suillcient mination of the undercut 6. lu rigidity to withstand the .pressure of the concrete In laying a section of roadway a concrete rewithout deforming but being readily bendable by taining rail R (Fig. 4) is secured in place so as hand or by means of a pair of hand pliers. The rto extend longitudinally along the middle of the blank is grooved or otherwise weakened along the road under construction, it being understood that bend line a forming the ridge of the casing l and a similar rail (not shown) is secured to the outer l5 also along the two bend lines b where the wings edge of the road. An initial layer of concrete C 2a and 3a join the sides of .the casing, forming 0f (approximately one-half the iinal proposed thickthe protector to proper shape without calling for ness of the roadbed) is poured between the rails, any special skill on the part of the workman. after which dowel bars B are laid horizontally Instead of being made of sheet metal as deupon this bed, usually over a wire reenforcing scribed above, the casing may be made of any netting N, with the ends of the dowel bars bent other suitable sheet material, such as paper, plasso as to extend closely adjacent and parallel to tic or wood. Also, instead of the Wires 4, other the rail R. meanssuch as pins, screws, bolts, or rivets- A protector is associated with each dowel bar may be used to hold the ends of the easing toby introducing the bent' end of the bar through 25 gether. Manifestly various other changes in conthe opening 1 so that the bar lies within the apex struction and design within the skill oi the art of the triangular casing, as shown in Fig. 4. One may be made in the protector described above wing of the protector is pushed down into the soft without departing from .the spirit of our invenconcrete and in contact with the rail R so as to tion as defined by the following claims.

retain the protector in place while the other We claim:

wing, also flatly abutting the rail, extends above 1. A protector for dowel bars comprising an the level of the concrete. Following this, anelongated casing made of sheet material adapted other layer of concrete C' is deposited between to receive a dowel bar, `the ends of said casing the rails on top of the rst layer C completely embeing closed, wings extending laterally from the bedding the dowel bars and protectors and raislower ends 0f both Sides 0f the Casing but 0f leSS ing the level o the roadway to the top of the rails. length than the casing, said easing being under- During the pouring of this final layer, `the plastic cut adjacent its ends, and a relatively small openconcrete ilows into the space between the undering in the top of the casing in the vicinity of one cut 6 and the inner face of the rail, thus locking of its ends through which the dowel bar may be the protector in the concrete. Since the ends of 4o slid endwise into the casing.

the casing l are secured .together by the tie wires 2. A protector for dowel bars comprising an 4 and because the wings 2a and 3a are pressedr elongated casing made of sheet material and of tightly into contact with the face of the rail generally triangular shape in transverse crossby the pressure of the concrete, the bent porsection, means .closing the ends of said casing,

tions of the dowel bars are effectively shielded wings contiguous with and extending laterally from the concrete, such little vconcrete as may from the lower` ends of both sides of the casing, ilow into the casing through the open bottom of said wings terminating a spaced distance from the undercut E being negligible. the ends of the casing, a relatively small opening After the concrete bed has set, the rail R is in the top of the casing in the vicinity of one of removed and the bent dowel bars B are straght- 5U its ends through which the dowel bar may be slid ened so as to extend over onto the other halfendwise into the casing, said casing being undersection of the roadway and are embedded in the cut from its ends to a point adjacent the wings, concrete composing that section when the roadand said opening being located beyond the unway is completed. The protector remains in the dercut area.

concrete when the roadway is iinished. Thus, in

the event frost, earth disturbances or other aca Y ROBERT A. MCGRATH, Sn.

tion causes the raising of one lane of the roadv ELLEN E. MCGRATH. 

